Comparison between effect of Azospirillum brasilense and Anabaena oryzae on growth, yield and anatomical characters of wheat plants

摘要

Bio-fertilization or inoculation with plant growth-promoting bacteria (PGPB) is a sustainable alternative for agro-ecosystems. Inoculation of wheat is a widespread agricultural practice that has proved to be efficient in increasing production and promoting nutrition of this crop. The greenhouse experiment was carried out to examine the effect of using biofertilizers (Anabaena oryzae and Azospirillum brasilens) on growth, yield and anatomy of three cultivars of wheat called Sakha 69, Sakha 93 and Gemaza7. A factorial design 3x3 with three replicates was applied. The morphological characters of wheat plants and anatomical studies were recorded after 80 days from sowing date and after physiological maturity grain and straw yield and grain and harvest index were determined. Culturable microorganisms were analyzed in rhizosphere samples which collected at 0, 60 and 120 days of planting and counts of most probable number of azospirilla and cyanobacteria were determined at the same time. Results showed a great variation in the effect of inoculation with different bio-fertilization on nitrogenase and dehydrogenase activities in rhizosphere of wheat plants. Inoculated soil with Az. brasilense and A. oryzae showed significant increase in all investigated morphological characters except number of leaves/plant. The interaction among biofertilizers and wheat cultivars proved significant effect on grain and straw yield as well as on weight of 1000 grains, while no significant effect on spike length and harvest index percentage. Anatomical studies showed the treatment of Anabeana oryzae or Azosprillium brasilense could be attributed to the increased in diameter of stem, thickness of mechanical tissue and parencymatous area of the ground tissue included vascular bundles. The mechanical tissue was increased by 40% for treatment with Anabeana oryzae and 33.2% for treatment with Azosprillium brasilense as compared with the control. Anabaena oryzae increased stem diameter of wheat plant cv Sakha 93, thickness of mechanical tissue , parenchymatous area of the ground tissue included vascular bundles, number of large vascular bundles , number of small bundles and diameter of metaxylem vessel by 30,8.2,14.3 31,7 and 39.9% more than those of the control; respectively. Anabaena oryzae increased stem diameter of wheat plant cv Gemaza 7, thickness of mechanical tissue , parenchymatous area of the ground tissue included vascular bundles, number of large vascular bundles , number of small bundles and diameter of metaxylem vessel by 34.8,40,24,32.2,26.6 and 16.5% more than those of the control; respectively. Azosprillium brasilense gave the same effect on anatomical characters of cv Sakha 93 and cv Gemaza 7.